Sensors for the detection of the position of a mechanical force-transmitting device are used, for example, in the case of windows regarding whose locking state a signal is to be communicated, for example to an alarm system or a system for building automation. This relates for example to the precondition for the arming of alarm systems which requires that all windows and doors must be in a closed and locked state. A further example is the use of the locking state of a window for regulating space heating systems which, with windows that are unlocked or open, for example end or at least restrict the supply of further heating energy for this space. Furthermore, a multiplicity of other exemplary applications are conceivable in which a detection and/or determination of the position of mechanical force-transmitting devices is advantageous.
Sensors suitable for the areas of application mentioned above are often provided with electronic circuits that communicate information to a remote evaluation device by means of a radio signal. This reduces the installation outlay by virtue of saving electrical leads for supplying the “radio sensors” with electrical energy. What is disadvantageous about this is the rising maintenance outlay therewith, since the supply with electrical energy that is realized by batteries has to be renewed at regular time intervals. A further disadvantage is the problem area of retrofitting with such “radio sensors”. The latter, due to the use of batteries as energy supply, usually cannot subsequently be fitted in concealed fashion. One example thereof is sensors of the abovementioned type in the case of window frames, or window levers.